Adjustable break-through torque wrench



Feb."2, 1954 R. E. GARwooD ADJUSTABLE BREAK-THROUGH TORQUE WRENCH Filed Feb. l2, 1951 Sm NY \m\ 0y WR. Y. Ww wc MN m 6m m am M m E R I RRQ ww Patented Feb. 2, 1954 2,667,800 ADJUSTABLE BRvlriK-THROUGH TORQUE ENCH Robert llLGarwood, Los Angeles, Calif., assignor to George G. Jenkins, doing business as Skyway Precision Tool Company, Los Angeles;

Calif.

Application February 12, 1951, Serial No. 210,557

(Cl. 8l-52.4)

2 Claims.

This invention relates to and more especially to a wrench of the torque type.

An object of the invention is to provide novel improvements in a WrenchV of the limited torque type. Y

Another object of the invention is to provide a torque wrench Yof improved type wherein a predetermined torque can be readily determined in machinery and tools limited An additional object of the invention is to provide a novel torque wrench wherein the limit of desired torque can be readily indicated and the tool adapted for adjustment to varying amounts of predetermined torque values.

Another object of the invention is to provide a torque wrench of novel construction of the break through type that is adjustable as to break through torque values and is adjustable as to a plurality of such values and having features for locking adjustment against accidental shifting.

Other objects and advantages will appear and be brought out more fully in the following specifloation, reference being had to the accompanying drawing.

In the drawing:

Figure 1 is a longitudinal sectional view of an embodiment of the present invention.

Figure 2 is a sectional view taken along the line 2-2 oi' Figure 1.

Figure 3 is a partial view in section showing the toggle link features seen in Figure l, shown in position after operation.

Figure 4 is a sectional view taken along the line 4-4 of Figure 1.

Figure 5 is a sectional view taken along the line 5-5 of Figure 1.

In the drawing the numeral I|i designates generally a wrench of limited torque embodying the present invention and comprising a tubular body and handle member II formed with a bore I2, open at both ends. A shell I3 is suitably secured to body member at one end and is provided with a side plate |4 secured to the shell by a plurality of bolts I5.

Shell I3 and plate i4 provide bearings for a spindle IB having square ends I1 for engaging the sockets of socket wrench elements, a lever arm I8 being integral with spindle I6 and having a pivot connection I9 to one end of a link 26. A cylindrical element 2| has a pivot connection 22 to link 20 and a link 23 is connected between the pin of pivot 22 and one of the shell bolts |5. Lever arm I8 is formed with a slot 24 through which extends one oi the shell cover bolts lia.

2 which serves to limit the movement of the lever arm.

Member has a threaded end portion 25 and a sleeve member 26 has a threaded bore portion 2l engageable with threads 25 of member Sleeve 26 has a threaded reduced bore 42 and a cylindrical spring seat element 23 has a threaded end portion 29 engaging in threaded portion 42 of the sleeve. A compression spring 3|! is positioned in bore 2 and seats against seat element 23 and cylindrical element 2|, a guide stem 3| for the spring being secured to element 2| if desired. Element 2B may have a similar spring guide stem 32 if desired. Seat element 28 is formed with a screw driver slot 33 to permit longitudinal adjustment of element 28 in the sleeve.

Sleeve 26 has a tubular end portion 34 into which extends a portion of body member II, the outer diameter of which portion 34 is reduced and a cam collar 35 is rotatable on this reduced portion. A holding collar 36 for cam collar 35 is secured on end portion 34 as by screws 31. Portion 34 is formed with a pair of longitudinal slots 33 in each of which is positioned a bearing roller 39 and sleeve 35 is formed with cam surfaces 40 of graduated diameters and is also formed with shoulders 4| for engaging rollers 39, Thus when collar 35 is rotated to the left as seen in Figure 5 cam surfaces 40 will engage rollers 39 and cause a locking engagement of the rollers with body member Il and prevent a rotation of sleeve 26 on body member Conversely when collar 35 after being thus locked is rotated to the right to the position as seen in Figure 5, the locking engagement is released and the sleeve 26 can be turned so as to either increase or decrease the compression of spring 30 in its engagement with element 2|. Collar 36 may be provided with scale indicia or other marking which will indicate the actual torque which the wrench will apply before operation of the toggle joint. In order to change the initial settings of this torque, seat element 28 may be adjustably positioned in sleeve 26 by use of the screw driver slot 33 as will be obvious.

In the operation of the invention a wrench socket element or other tool may be connected to the lower end |1 of spindle i6, for example, and upon right hand rotation of the wrench as seen in Figure 2, a torque will be applied to the connected tool and upon the limit of torque being reached as determined by the particular setting oi sleeve 26, toggle link |3-2Il will shift to the position shown in Figure 3, the movement of link I8 being limited by bolt |50 engaging the end of slot 21. This toggle link movement can be readily felt and heard by the operator of the tool and he will know that the indicated torque has been reached. The wrench I0 can however be `given further tightening rotation if the operator particularly desires to do this, however he will be aware that this applied torque is in excess of that indicated by the setting of sleeve 26. It will be seen from Figure 3 that pin I9 which connects link I8 and link 20 does not move to the center line of spindle IE and pin 22 and therefore upon release of the applied torque t'he' to'gg'l'e link 'will be sprung back to the position shown in Figure 1.

While in the foregoing there has been shown and described the preferred formofrthisinvention, it is to be understood that xminor changes in the details of construction, combination and arrangement of parts may be resotdto without departing from the spirit and scope of theinvention as claimed.

I claim:

1. In a torque wrench of the class described, a hollow shell open at its ends and at one of its sides,` a cover plate closing the open side, several bolts passing through the shell removably securing said cover plate in place, a transverse tool spindle mounted in one end of the shell, an arm extending inwardly of the shell from said spindle, a tubular body having an end secured in the other end ofthe shell, a reciprocating stem within said body, a cylindrical head carried at one end of said stern and having a reduced portion projecting into theshell. a pair of laterally disposed links pivotally connected with one of said bolts at one of their ends and at opposite sides of said reduced portion, a second pair of links pivotally connected; at one of their ends at opposite sides of said reduced portion commonly with the first pair of linksA and at their other ends with and at opposite sides of the free end of said arm, said arm and said links constituting a forni oftoggle, a sleeve, constituting a handle, telescoped on the other end of said body and in threaded engagement therewith, a compression spring within said body and encircling said stem with one end bearing against said head, an adjustable member, constituting a seat for the opposite end of said spring, within the other end of said body and having threaded engagement with the outer e doi sa seEVe, so that by reversely turning hef after gaiyely to the body, the compression of the spring will be correspondingly varied, and cooperative means mounted o n said body and said sleeve for locking t'h'lattr ag'ainstrelative turning movements with respect to the body.

2,. 'Ilieinyentionasxdened in claim 1, with the said locking fmeans comprising an annular cam element mounted forYturning movements on the inner etndof` said sleeve. the inner end of said sleeve having a' pair of oppositely disposed longitudinaLslots underlying said cam element, a roller engaged in each of said siots and having contact with the surfaceoflsaidody, andan adjusta le stop collargmountedon said body'iii abuttedr aftion with respectto'the adjacent ends of saidl sleeve and the cam elernent.

' QOBERTVE. GARWOQD.

References Cited inl the ileV 0fA 1311,154 RafteQ,

UNITED sTArns PATENTS 

